Spreader or sprayer and control system therefore

ABSTRACT

A vehicle mounted spreader for spreading materials such as sand, salt, or other granular chemicals onto snow and ice covered road surfaces comprises a hopper for containing the material to be spread, a spinner for spreading the material, a conveyor for conveying the material from the hopper to the spinner, a vehicle speed sensor, a load sensor, and a controller programmed with an intended density of material (e.g., pounds per acre) and desired width of coverage; within the controller the vehicle speed sensor measurement and load sensor inputs are processed to generate outputs to control the speed of the conveyor and spinner, to both control the rate of material distribution and the pattern of material distribution to approach the intended density and width.

RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional Patent Application No. 63/269,947 filed Mar. 25, 2022, which is hereby incorporated by reference herein as if fully set forth in its entirety. U.S. patent application Ser. No. 16/117,123 entitled SPREADER filed Aug. 30, 2018, and U.S. patent application Ser. No. 16/277,647 entitled SPREADER WITH SHAFTLESS AUGER filed Feb. 15, 2019, are both hereby incorporated by reference herein as if fully set forth in their entirety.

FIELD OF THE INVENTION

This invention relates generally to snow and ice control, and more particularly to spreaders and sprayers for spreading and spraying snow and ice melt materials onto snow and ice covered road surfaces.

BACKGROUND OF THE INVENTION

Spreaders for spreading salt or other granular chemicals for melting snow and ice on road surfaces, or for spreading abrasives such as sand for otherwise reducing the deleterious effects of snow and ice on road surfaces, are well known. As used herein, “road surface” or “paved surface” or simply “surface” shall embrace concrete, asphalt, tar-and-chip, gravel, and dirt surfaces. One type of spreader is mounted on or in a bed of a truck, has a hopper for containing the material to be spread, a spinner for spreading the material onto the pavement, and an auger or chain conveyor for moving the material from the hopper to the spinner.

Sprayers for spraying brine for melting snow and ice on road surfaces are also well known. One type of sprayer is mounted on or in a bed of a truck, has a tank for containing the brine to be sprayed, a nozzle array for spraying the brine onto the pavement, and a pump and hoses for moving the brine from the tank to a perforated hose or nozzle array to spray brine on the material being spread.

Snow and ice control professionals currently do not have precise control of the volume and area of the distribution of snow and ice control material, whether that material be a solid such as sand, salt, or granular snow/ice melt chemical, or a liquid such as salt brine or calcium chloride brine. Application is difficult to measure as it is influenced by many variables, chiefly the rate with which material is moved out of the hopper or liquid tank, the speed of the vehicle, and the pattern of the material distribution, which is typically controlled by the speed of the spinner and the position of deflectors, in the case of spreaders, and the position of liquid nozzles, in the case of sprayers.

Current processes are based on manually controlling these three variables and estimating results which lacks precision and is prone to over-applying, under-applying, or inconsistently applying material. Potential consequences include inadequate material coverage resulting in unsafe surfaces, excessive coverage resulting in wasted material, inaccurate customer billing, and violation of environmental standards or regulations. These consequences all present legal or financial risk for the operator.

These problems are magnified for the owners and managers of fleets of vehicles who must track the application of material for multiple vehicles with snow and ice control equipment that are operating simultaneously in multiple locations. The collection of data from these fleets is difficult, relies on imprecise estimates, and cannot be done in real-time. This presents complicated challenges to the efficient allocation of equipment and material, billing and quality assurance, and the tracking of equipment and job status.

Control and tracking of the application of de-icing material is currently primarily based on estimation and manual inputs. In some cases calibrated assumptions about material application are used for these estimates, which simplifies estimation but does not actually measure the material and is therefore not reliable, particularly as additional variables change. Furthermore, calibration is an undesirable process to the customer and fails to account for variables in the material or environment. Solutions to offer location information and improved connectivity also exist but are unable to provide the material usage data with the desired precision.

Accordingly, snow and ice control equipment and a control system therefore is desired that is capable of precisely controlling and tracking snow and ice melt material distribution, and facilitating real-time fleet management.

SUMMARY OF THE INVENTION

In one aspect, a vehicle mounted spreader for spreading materials such as sand, salt, or other granular chemicals onto snow- and ice-covered road surfaces comprises a hopper for containing the material to be spread, one or more load sensors coupled to the hopper for measurement of the hopper contents, a spinner for spreading the material, a conveyor for conveying the material from the hopper to the spinner, and a vehicle speed input, where the load sensor, spinner, conveyor, and speed input are coupled to a controller. The controller is programmed with an intended density of material (e.g., pounds per acre) and desired width of coverage; within the controller a vehicle speed measurement and load sensor inputs are processed to generate outputs to control the speed of the conveyor and spinner, to both control the rate of material distribution and the pattern of material distribution to approach the intended density and width.

In one particular embodiment, within the controller, an assumed output rate developed from a current spinner and conveyor rate is adapted using real-time load sensor readings, such that the controller refines the output rate and adjusts the speed of the conveyor toward the intended density of material. Further, the controller may actively control the speed of the spinner to achieve a desired width of coverage.

Further embodiments comprise a human interface, and the controller may provide feedback information via the human interface to an operator. The feedback information may include a range within which vehicle speed must be maintained to permit accurate control of the rate of material distribution at the target density.

Some embodiments further comprise a wireless communication system, and the controller may be coupled to the wireless communication system to deliver feedback information from the controller to a remote server, from which it may be accessed by interested persons. The information provided may include historical measurements of coverage density and width of coverage, speed, and load sensor data. Vehicle speed may be obtained by the speed input from a vehicle diagnostics port and/or the controller may further comprise a positioning system producing location and motion information and deliver location and motion information to the speed input of the controller, the human interface and/or the remote server. The controller may also receive instructions from a dispatcher via the wireless communication system, for delivery to the human interface.

In one embodiment of the controlled mechanical system, the spreader can comprise a cradle supported by the vehicle, the cradle including at least one load cell serving as a load sensor, with the hopper supported by the at least one load cell. The conveyor can be an auger or a chain conveyor. In other embodiments within the scope of the present invention, the conveyor could be a belt conveyor.

In another aspect, a vehicle mounted apparatus for distributing snow and ice melt material onto snow- and ice-covered road surfaces comprises a container for containing the material to be distributed, means for distributing the material, means for conveying the material from the container to the means for distributing the material, and a controller controlling the distributing means and conveying means in response to a measurement of the quantity of melt material in the container, the controller programmed with an intended density of melt material (e.g., pounds per acre) and desired width of coverage; within the controller a vehicle speed sensor measurement and vehicle load sensor inputs are processed to generate outputs to control the speed of the conveyor and spinner, to both control the rate of material distribution and the pattern of material distribution to approach the intended density and width.

The apparatus can further comprise a cradle supported by the vehicle, the cradle having at least one load cell providing the load sensor input to the control system, the quantity of material in the container measured by at least one load sensor. The container can be a hopper, the material can be sand, salt, or other granular chemicals, the means for distributing the material can be a spinner, and the means for conveying the material can be an auger or a chain conveyor. Alternatively, the container can be a tank, the material can be brine, the means for distributing the material can be a nozzle array, and the means for conveying the material can be a pump and a hose, or a belt conveyor.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the summary of the invention given above, and the detailed description of the drawings given below, serve to explain the principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top right rear perspective view of a vehicle and one embodiment of spreader of the present invention.

FIG. 2 is an enlarged top right rear perspective view of the spreader of FIG. 1 .

FIG. 2A is an exploded perspective view of FIG. 2 .

FIG. 3 is a cross-sectional view of the spreader taken along line 3-3 in FIG. 2 .

FIG. 3A is a cross-sectional view of the spreader taken along line 3A-3A in FIG. 3 .

FIG. 4 is a top view of the spreader of FIG. 1 .

FIG. 5 is an enlarged top right rear perspective view of another embodiment of spreader of the present invention.

FIG. 6 is a cross-sectional view taken along line 6-6 in FIG. 5 .

FIG. 7 is a top view of the spreader of FIG. 5 .

FIG. 8 is an information flow diagram for the controller used in the control system of the present invention.

FIG. 9 is a diagrammatic top view of the spreader and material application area.

FIG. 10 is a block diagram of the control system implemented with the controller of the present invention.

FIG. 11 is a graph depicting empirical characterization curves and data points from which those curves were derived, for the relationship between motor current and flow rate for a given motor at several PWM duty cycle settings.

FIG. 12 illustrates a liquid plumbing system for producing a mixture of brine and hot mix to various delivery points in an alternative embodiment of the present invention.

FIGS. 13A, 13B and 13C illustrate display screens produced to an operator to enable proper management of vehicle speed for product delivery.

FIGS. 14A, 14B, 14C, 14D, 14E and 14F illustrate display screens presented to a service provider remote home office to enable control and tracking of product delivery.

FIG. 15 illustrates a spreader in accordance with principles of the present invention when protective housings have been installed.

FIG. 16 illustrates the components of a pre-wetting attachment in accordance with one alternative embodiment of the invention.

FIG. 17 is a functional diagram of components of the pre-wetting attachment seen in FIG. 16 .

DETAILED DESCRIPTION OF THE DRAWINGS

Referring first to FIG. 1 , a vehicle 10 has mounted on it a spreader, sometimes referred to as a hopper spreader, 20 according to the principles of the present invention.

Referring FIGS. 2-4 , the spreader 20 has a material container in the form of a hopper, sometimes referred to as a V-hopper, 22 for containing the material to be spread, a spinner 24 for spreading material, and an auger 26 for conveying the material from the hopper 22 to the spinner 24. Spinner 24 is powered by a motor and gear box 28 (FIG. 3 ). Auger 26 is powered by a motor and gear box 30. For the purposes of clear illustration of the relevant functions, safety guards or housings that would typically enclose the spinner and other mechanical parts seen in the figures, are not shown, but would be in place in a typical implementation.

A cradle 32 is supported upon a bed 34 of vehicle 10. Cradle 32 may be mounted to the bed 34 with by various means (not shown), to allow re-purposing of the vehicle during summer months by removing cradle 32. One mounting method may utilize bolts through the bed or frame, potentially combined with removable straps, or other more permanently mounted devices. Cradle 32 has four load cells 36 supporting hopper 20. Load cells 36 develop signals indicative of the weight of the hopper 20, and hence the quantity of material in hopper 20, which are delivered to a controller 40, typically through an interface module in a controller area network, as discussed below. The cradle and load cells collectively form a scale system that produces material load data. Although in the disclosed embodiment the load data comes from a load cell, other forms of load sensors may be used. In the disclosed particular embodiment, the scale system's structure is assembled with profiled and formed stainless steel parts that are bolted together and/or riveted together, with stainless steel machined blocks used for mounting the load cells beneath each “leg” of the hopper. Load cells used in this embodiment may be obtained from Scale-Tec of 16027 Hwy 64, East Anamosa, IA 52205; however, the system can be made to work with other load cells as well, using alternative components. Various other configurations are feasible, so long as the weight of the hopper is transmitted to the load cells to permit accurate measurement. Furthermore, the configurations of components shown in FIGS. 2A et seq. are merely exemplary and could be varied without change to the patented functionality. For example or of both of the legs of the hopper may be positioned differently, or their orientations reversed from the positions shown.

Referring to FIGS. 5-7 , an alternative embodiment of spreader 20 is shown. In this embodiment, a chain conveyor 42 has been substituted for auger 26 of the prior embodiment as the means of conveying the material from hopper 22 to spinner 24. Here again, for the purposes of clear illustration of the relevant functions, safety guards or housings that would typically enclose the spinner and other mechanical parts seen in the figures, are not shown, but would be in place in a typical implementation.

Referring now to FIG. 8 , the information flow of controller 40 in accordance with principles of the present invention can be elaborated. Information is delivered either directly or indirectly (e.g., via a controller area network) from the various and several sources shown in FIG. 8 . Controller 40 produces auger/conveyor speed control signal 50 and spinner speed control signal 52 in response to a vehicle speed 44, a programmed application rate setpoint, an application width setpoint 48, and the input of a load sensor 49 indicative of the material weight.

Load sensor may be the load cells 36 discussed above, potentially supplemented for user interface or redundancy/fail-safe purposes with a tank level sensor in the case of delivery of brine material. In the case of delivery of brine material, the auger / conveyor speed control signal 50 can be a pump control for a brine pump. In one embodiment, a flow sensor in the brine supply path may be used to track the flow of brine, or power consumption by the pump may be used as a measure of the flow rate of brine through the pump.

Vehicle speed 44 may be gathered from the vehicle or from a global positioning system (GPS) integrated into or coupled to control 40. Application rate and width setpoints 46 and 48 may be pre-programmed, programmed via the human interface 56, or remotely programmed via wireless modem 54.

The controller may be implemented as one device in a central housing or as multiple distributed devices connected by a communication network. In one embodiment the controller area network (CAN) protocol is used for the networked communication; communication over CAN uses two conductor, twisted pair connections. CAN is electrically resilient in the presence of noise which is why CAN is typically used for vehicle control systems. As one example, load cells 36 may be connected to a load sensor module of the controller area network which receives electrical signals from load cells 36 indicative of material quantity, converts those signals to material quantity data, and relays that data to other devices in the controller network in CAN format. The particular communication method and communication network structure utilized to convey information to the controller may vary without impact upon the principles of the present invention.

Vehicle speed 44 may be acquired by a GPS receiver/antenna using GNSS technology (satellites, sensitivity, etc.) to produce vehicle speed, and optionally location, data at an acceptable reporting rate such as 10 Hz or more, which is sufficient to enable precision control of the spreader rate. GPS further provides high accuracy date and time information.

Controller 40 may include Bluetooth low energy (BLE) circuits and a corresponding antenna to enable wireless communications to other on-board vehicle systems using BLE protocol wireless communications. BLE connections may be used to connect and supply information to a service provider mobile application over a Bluetooth connection to a smartphone or tablet, thus implementing the user interface with user-supplied hardware. BLE communications may also be used for device configuration, calibration, updates, and any other setup operations that are required by the controller or connected devices. BLE may also allow a technician with a suitably programmed BLE compatible device to read status and error codes for onsite troubleshooting of the system, and enable communication with a Bluetooth enabled user device to perform remote diagnostics and live troubleshooting via technical support staff. BLE may also be used to form a personal area network (PAN) cable of collecting data from trackable ancillary assets such as snow shovels and brooms equipped with bluetooth-enabled trackers such as those sold by Tile, a divisional of Life360, Inc. of San Mateo, California. 2.4 GHz BLE radios enable a cost effective and reliable network for connecting this class of device.

Controller is configured with a processor and non-volatile memory used for storage of configuration settings that persist across power cycles and/or lost connectivity.

Controller 40 may further optionally include an on-board diagnostics (OBD-II) interface to connect to the vehicle Engine Control Unit (ECU) via its OBD-II port. The information obtained from this connection can include performance data (fuel consumption, Diagnostic Trouble Codes (DTCs) and ground speed, as well as providing useful setup and configuration information.

Wireless modem 54 is preferably an LTE or 5G cellular modem, enabling connection to the internet. Specifically, the modem may be an LTE-M modem specifically designed for IoT connectivity using low cost data plans enabled by a removable Subscriber Identity Module (SIM) card or using Embedded-SIM (eSIM) technology.

Controller may advantageously include sufficient nonvolatile storage to retain a data log, particularly a queue of data from the system which may be retained in the event of data loss or to permit resilience in the event the wireless modem/LTE/5G Internet communication is sporadic or temporarily unavailable. A memory size sufficient for a month of “typical” system usage data retained in the data log would be advantageous by providing a proof of service record. Additional memory space is allocated for buffering over the air updates as they are downloaded from a remote server.

Controller 40, and/or the controller area network modules which collectively form the controller, may be implemented in an IP67 rated water Ingress Protected (IP) housing, with connector ports that for plug-in of wired accessories, in a plastic molded outer cover providing apertures for control cable routing and permitting visibility of one or more status indicator lights.

FIG. 9 provides useful definitional information for explanation of the control strategy used by controller in accordance with principles of the present invention. As seen in FIG. 9 , the covered surface area is a function of the width W of coverage created by the current spinner speed, and the vehicle speed VS (km/h) multiplied by the time t over which material was spread. The coverage area is calculated as (factor of 1000 for units conversion of km/h to m/h):

-   -   Coverage Area=Application_Width×Vehicle_Speed×1000×Time     -   The total amount of material dispensed is calculated as:     -   Total Material=Discharge_Rate×Time     -   The Application_Rate is calculated as:     -   Application_Rate=Total Material/Coverage Area     -   Based on the above, one can solve for the Discharge_Rate:     -   Application_Rate=(Discharge_Rate×Time)/(Application_Width×Vehicle_Speed×1000×Time)     -   Discharge_Rate=Application_Rate×Application_Width×Vehicle_Speed×1000

The control of the discharge rate is provided by a control system including the controller 40, operating a control strategy. In an embodiment using an auger conveyor, the following are the inputs and outputs:

Units Term Type (SI) Description Application_Rate Input kg/m² Rate at which solids are discharged from the hopper Vehicle_Speed Input km/h Forward ground speed of the vehicle Application_Width Input m Desired ground spreading width of solids Material_Weight Input kg Weight of solids material in the hopper Spreader_Height Input in Distance from the ground to the top (TBD) of the spinner plate|

Spreader_Height, included in the list above, for potential use cases where there is an adjustment to the spreader height (not shown in the present embodiment); spreader height adjustment affects Application_Width and thus could be captured and accommodated if the height is adjustable.

Units Term Type (SI) Description Spinner_Speed Output % Drive percentage (PWM output) to the spinner plate motor Auger_Speed Output % Drive percentage (PWM output) to the hopper auger motor Auger_Speed_Clip Output bool Indicates if the auger speed is being clipped (unable to keep up with demand) Spinner_Speed_Clip Output bool Indicates if the spinner speed is being clipped (unable to keep up with demand)

The following parameters are derived

Units Term Type (SI) Description Discharge_Rate Derived kg/h Rate at which solids are discharged from the hopper Auger_Rate Derived % / kg/h Relationship between the Discharge_Rate and Auger_Speed

The following parameters are used for configuration:

Units Term (SI) Description Min_Vehicle_Speed km/h Minimum speed before smart control is permitted Max_Vehicle_Speed km/h Maximum speed at which smart control is permitted Min_Auger_Speed % Auger drive output limited to this minimum value Max_Auger_Speed % Auger drive output limited to this maximum value Min_Spinner_Speed % Spinner drive output limited to this minimum value Max_Spinner_Speed % Spinner drive output limited to this maximum value Spinner_Rate %/m Rate at which spinner is adjusted based on width Spinner_Offset % Offset of spinner speed adjustment

At the top level, the controller performs this control strategy based upon three inputs, to produce two outputs. The three inputs are Vehicle_Speed 44, Application_Rate 46, and Application_Width 48. The outputs of the control strategy are Auger_Speed 50 (or flow rate for a brine application embodiment) and Spinner_Speed 52.

As seen in FIG. 10 , using these inputs, the controller implements a feed-forward control with a system model that is continually monitoring performance via system feedback (material weight 60 identified by a load sensor) and periodically updating the feed-forward control variable, which is the Auger Rate 64.

The determination of the Auger_Speed (50) is computed as:

-   -   Auger_Speed′=Auger_Rate×Discharge_Rate     -   Where Discharge_Rate 66 is computed from         Application_Rate×Application_Width×Vehicle_Speed×1000 as derived         above.     -   The Auger Limiter 62 is used to provide an Auger_Speed value         that is conditioned from Auger_Speed′ as follows:     -   1. If Auger_Speed′<Min_Auger_Speed, then         Auger_Speed=Min_Auger_Speed     -   2. else if Auger_Speed′>Max_Auger_Speed, then         Auger_Speed=Max_Auger_Speed     -   3. else Auger_Speed=Auger_Speed′

In addition to the foregoing, the controller 40 computes control limits for the purpose of providing feedback to the operator regarding effective operating ranges, as follows:

-   -   Max_Auger_Speed=Max_Control_Discharge_Rate×Auger_Rate     -   so     -   Max_Control_Discharge_Rate=Max_Auger_Speed/Auger_Rate     -   and     -   Max_Control_Discharge_Rate=Application_Rate×Application_Width×     -   Max_Control_Vehicle_Speed*1000     -   Solving for max speed:     -   Max_Control_Vehicle_Speed=1000×(Application_Rate×Application_Width)/Max_Control_Discharge_Rate

The Auger_Rate is computed by correlating the predicted spreader performance with the measured data from the scale. Due to the significant noise inherent in a vehicle mounted scale system, a novel approach is implemented. A least-squares regression is repeatedly performed to determine the correlation slope as the auger rate is adjusted on the predicted performance data until the slope is near a value of one, which aligns with an auger rate value that very closely matches the recorded data for that time period.

Spinner_Speed=Application_Width*Spinner_Rate+Spinner_Offset

BRINE—LIQUID APPLICATIONS

In brine applications, in one embodiment, an in-line flow meter may be used to measure flow of brine, however, the flow rate of liquid may alternately be controlled using a novel approach involving sensing of power consumption of the pump relative to the PWM output of the controller. This method is described in this section.

The liquid application flow rate is set by the main control system based on several parameters. In a typical direct liquid application, the flow rate is determined by a desired application density and vehicle speed. In alternative or enhanced embodiments, the system may also support a pre-wet application, using a pre-wet accessory or attachment (see FIGS. 16-17 , below). To support such an accessory the main control system would determine a desired salt application density, and desired water to salt ratio, and establish the flow rate and target vehicle speed from these additional variables.

Because this sub-system uses a diaphragm pump to move the liquid, the pressure in the plumbing and the current consumption of the pump motor are strongly correlated. Further, fluid flow is the result of pressure differential within a fluid system, and therefore, the fluid flow rate is also correlated with the pump's current consumption.

Because the controller is aware of the pump's duty cycle, the control algorithm can effectively follow a pressure vs current curve generated by a characterization process for discrete duty cycle settings.

The plot of FIG. 11 shows the data that was collected and the resultant mathematical model curves for a given motor and PWM (duty cycle).

Implementing this model, in one exemplary embodiment, the firmware in the controller has functions that solve for the flow rate based on the empirical characterization curves of FIG. 11 . The firmware can also interpolate between the discrete curves for duty cycles (PWM Values) between those shown below.

The controller sets a liquid flow rate setpoint and an initial PWM duty cycle to start the flow of liquid.

Under normal conditions at the startup of the pump, the duty cycle can be set to a nominal value based on the characterization curve and should provide a flow rate very close to the set point. The controller then measures the pump's current consumption.

Using the current consumption and the known duty cycle, the controller can then determine the flow rate of liquid from the model curves shown in FIG. 11 .

The controller then adjusts the pump duty cycle appropriately until the flow rate calculated from the current consumption satisfies the setpoint.

Notably, the outlet orifice may change due to wear or build-up of deposits, causing a pressure change within the plumbing system that impacts the flow rate for a given duty cycle. If the orifice becomes larger, the pressure drop decreases (current consumption also decreases), and the flow rate increases. If the orifice becomes smaller, the pressure drop increases (current consumption also increases), decreasing the flow rate. The following scenario demonstrates this logic:

Assume the orifice is of nominal size, the pump is operating at a given PWM value (duty cycle) of 4 in the plots of FIG. 11 , and the desired flow rate is 1.25 GPM. At this condition the current consumption is 10A.

Assume that the orifice is made larger due to wear, i.e. the pressure drop and current decreases to 9A and the flow rate is now ˜1.5 GPM, and the duty cycle is unchanged.

In an open-loop system, this condition would go undetected. However, by measuring the pump's current consumption according to the described method, the controller will calibrate for this change of circumstance. Specifically, the controller will adjust the duty cycle downwards in the described scenario. By interpolating the curves between PWM 2 and PWM 4, one can see that the appropriate duty cycle for a setpoint of 1.25 GPM would be ˜PWM 3.

In FIG. 11 , the curve-fit regression lines inform the algorithm how the flow rate will change as the power consumption is changed for a given orifice size that corresponds to the index value of the data point along each PWM curve.

Consider that upon initial start of the pump, the set point is 1 GPM.

For the sake of illustration, the nominal orifice and pressure drop could be established to correspond to the size of the orifice used to generate the data point at index value 12 along the curve.

Using the illustrated curves, with this nominal orifice, to achieve a 1 GPM flow rate, the duty cycle should be set to PWM 2 which would be expected to cause ˜6 amps of current consumption.

In this nominal system, the regression line may be used to determine the flow rate for each given duty cycle/current consumption (PWM 2, PWM 4, PWM 6 or PWM 8, each represented by one of four associated regression lines).

Regression between the lies shown in FIG. 11 is accomplished based upon current consumption. For example, in the example above, where ˜6 amps of current consumption would be expected, consider a case where upon measuring the current consumption, it is found to actually be ˜7.5 amps.

This indicates that some deposits have built up in the plumbing causing a larger pressure drop and therefore a lower flow rate. Using the PWM 2 regression line, the actual flow rate can be estimated to be of ˜0.75 GPM.

This regression process, when performed by the algorithm allows the system to recalibrate on the basis that the effective orifice size corresponds to the orifice size used to generate the data points at index value=21.

From the characteristic data and the live data combined, the system thus will have an understanding of the effective orifice size in the plumbing.

At this point, the algorithm can take advantage of the regression lines to inform the system how to adjust the duty cycle of the pump to achieve the desired set point. For example, to restore a 1 GPM flow rate, the process can be visualized by following the line from Index 21 until it intersects with 1 GPM on the vertical axis. In this data set, this would correspond to setting the duty cycle to ˜PWM 3 or in other words, adjusting the duty cycle until the current consumption is ˜9 amps.

It should be noted that this algorithm could be used to notify a user of changes in the plumbing up stream of the pump. For example, in the event the pre-pump filter becomes clogged with algae and biological matter, this can dramatically impact performance, particularly where the pump is a diaphragm pump that is significantly limited in its ability to produce a vacuum as compared to its ability to create positive pressure. In some of the extremes of the experiment, this was sufficient to limit flow into the suction side of the pump. In such a scenario, both the flow rate produced and current consumption were significantly reduced. This is because when the pump is unable to draw fluid in during the suction cycle, the diaphragm(s) collapse under the vacuum. This results in the diaphragms being unfilled or under filled when the pump reaches the compression cycle, greatly reducing flow and output pressure which effectively means the pump motor is freewheeling, resulting in the drop in current consumption as well.

FIG. 12 illustrates a liquids plumbing system 100 for producing a mixture of brine and hot mix to various delivery points in one particular alternative embodiment of the present invention, illustrating a manner in which principles of the present invention may be applied to application of liquids from a tank. In this embodiment, brine is delivered from a main brine tank 102 via flex hose 104 and a manual valve 106 to a strainer 108 where any particulate of concern is removed. (A fill port 110 also connects via this path, accessible by removing a cam lock cap 112 to expose the cam-lock fill port 110, which can be used for filling by opening a manual valve 114.) Brine passed through the strainer 108 is delivered via a check valve 116 to a 12V DC centrifugal pump 118, the output of which is delivered via a check valve 124 to a mixing valve 126. The pressure of the delivered brine is detected by a pressure gauge 120 which controls an electromechanical valve 122 in a recirculate path back to the main brine tank 102; valve 122 is opened and closed to manage brine pressure and mixing.

Hot mix (also known as enhanced salt brine) may also be delivered for mixing with the main brine solution via a second delivery system including a hot mix tank 130, which delivers hot mix through a manual valve 132 and 12 Volt DC pump 134; the flow rate or pressure of hot mix is controlled by a recirculating electromechanical valve 136 coupled to the Hot Mix tank, and a second electromechanical valve 138 which delivers hot mix through a check valve 140 to the mixing valve 126.

In the illustrated embodiment, mixed brine and hot mix emerge from the mixing valve 126 into a flow meter 142 which measures delivery rate of the mixture. The output of the flow meter is delivered to one of several delivery points, including a passenger side sprayer 146, center sprayer 150 and driver side sprayer 154, each of which has an output controlled by a respective electromechanical valve 144, 148 and 152, using the control strategies discussed herein. In addition, a manual valve 156 coupled to the flow meter output delivers brine and hot mix to a hand sprayer on a hose reel 158, allowing manual delivery of product by an operator in special treatment situations.

Referring now to FIGS. 13A-13C, one embodiment of the displays generated by the smart controller 40 on human interface 56 provides simplified feedback to the operator by way of visual cues as to whether the current vehicle speed is in a proper range to permit product delivery at the current set point. As seen in FIG. 13A, in the case the vehicle is traveling at too fast a speed to permit adequate product delivery (product cannot be delivered rapidly enough), a prompt is provided to visually indicate excessive speed (e.g., a background color red) and to provide corresponding text such as “Slow Down.” As seen in FIG. 13B, when the vehicle is not traveling fast enough to permit product delivery (product cannot be accurately delivered slowly enough for the current speed), a prompt is provided to visually indicate insufficient speed (e.g., a brown background color) and to provide corresponding text such as “Speed Up.” FIG. 13C illustrates a display indicating the vehicle is moving at an appropriate speed, visually indicated (e.g., by a green colored bar graph). Each display includes additional information in an intuitive fashion, such as the rate of product delivery (“Rate”), the amount of remaining product (“Material”), the current speed (“Speed MPH”), the width of product delivery, and the amount of remaining liquids (bar graph with droplet icons).

Referring now to FIGS. 14A through 14F, an embodiment of a central tracking interface for use in conjunction with the present invention can be elaborated. The premise of this central interface is to “capture all work done”. In this spirit, a web application powered by a server collecting data from the various vehicle controllers (via wireless modem 54) presents various screens to allow service providers to track and report on the work their organization is providing to various customers. Due to the novel “Smart Spreader Control Algorithm” and the hardware capabilities of the supporting hardware described herein, the web application is able to report on material usage and service visit details.

FIG. 14A shows the map view in which the locations of vehicles where work is being done can be displayed to a central dispatcher. FIG. 14B shows an alternative map view with details of particular operators and vehicles in service and their locations, current status, and product quantities remaining. FIG. 14C is an expanded display showing the real time status of the equipment in the field including operators, vehicles, product levels and status of completion of assigned routes. FIG. 14D shows a map view in which the activity of a vehicle during a prior operation (location history) is presented for the purpose of verification and audit of activity. FIG. 14E is an alternative view of detailed data relating to a service visit, including details of the operator, equipment, material use, and any notes from the service provider relating to the service provided. FIG. 14F shows a still further alternative presentation of data relating to a service visit, including all visits to a particular location and the details thereof.

The invention thus provides a unique and novel controller and control strategy for the delivery of material accounting for and addressing the flaws and weaknesses of existing systems and providing for a greater level of communication thereon with the operator and remote servers and managers.

The various embodiments of the invention shown and described are merely for illustrative purposes only, as the drawings and the description are not intended to restrict or limit in any way the scope of the claims. Those skilled in the art will appreciate various changes, modifications, and improvements which can be made to the invention without departing from the spirit or scope thereof.

For example, the load sensor might be implemented other than with a load cell, such as by using a short-stroke hydraulic ram coupled to a pressure transducers for bearing the weight of the hopper. Furthermore, in a more fully integrated embodiment, the load cell (or other load sensor) could be integrated into an outer structure of the hopper-spreader with the hopper and its material load cradled by the sensors. Other methods of measuring the weight of the hopper and its material load could theoretically be used as well including pneumatic systems to measure air pressure or deflection sensors to measure changes in material surfaces when loaded. On-vehicle systems might also serve as a load sensor, such as a tire pressure measurement system or rear air suspension system. Additionally, liquid material flow could be measured with a flow meter rather than a fixed-displacement pump controlled by a pulse width modulation method.

The positioning of the controller and its method of integration into the hopper/conveyor/spreader system could be implemented in numerous ways without departure from the spirit and scope of the invention. Communication to a human interface in a vehicle cab could use wireless communication, to eliminate the need for cabling a vehicle to use the system. The controller and modules may particularly use Bluetooth Low Energy (BLE) wireless links.

In some embodiments the controller may include a video input for receiving video from remote cameras, for storage or delivery locally to the human interface 56 or to a remote server via modem 54. Further, the controller may include a pavement sensor(s), such as a laser or infrared temperature sensors, for evaluating road condition and including that data in the control strategy of the controller.

Connection of the controller to the wireless modem, human interface, or other components may utilize a dedicated communications port, or may be done on a shared CAN (controller area network) bus connection or RS-485 vehicle bus, depending upon the compatibility with existing vehicle systems and desired level of interconnection.

Connection to the OBD-II port may use a wired connection from the OBD-II port on the vehicle to the controller, or a wireless connection device such as the Vgate iCar Pro may be used to interface the available CAN status and diagnostic information to a BLE format.

FIG. 15 illustrates the spreader 20 when the protective housings have been installed on hopper 22, spinner 24, and other parts of the cradle 32. FIG. 15 also shows the pre-wetting attachment 160, which is discussed in greater detail below.

FIGS. 16 and 17 illustrate the components of a pre-wetting attachment. As discussed above, pre-wetting is used in snow removal to help increase the effectiveness of salt and de-icing agents. It involves applying a liquid de-icer to the road surface before or during the application of solid de-icers, such as salt.

When pre-wetting, a liquid de-icing agent, typically a salt brine solution or magnesium chloride solution, is sprayed onto the road surface before the solid de-icer is spread. This can help to activate the solid de-icer more quickly, because the liquid de-icer helps to dissolve and spread the solid material, creating a slush that can help to break down ice and snow.

Pre-wetting can be especially effective in colder temperatures, because the liquid de-icer can help to lower the freezing point of the ice and snow, making it easier to melt. In addition, because pre-wetting can help the solid de-icer to adhere to the road surface more effectively, it can reduce the amount of salt or de-icer needed to achieve the desired level of snow and ice control, which can save money and reduce environmental impacts.

As best seen in FIG. 17 , the pre-wetting system comprises a ball valve 162 for controlling pre-wetting fluid flow, a strainer 164, and a pump 166 that is controlled to provide a desired amount of pre-wetting fluid. Pre-wetting fluid is directed by a T-valve two one of two places: toward the material being delivered by the spinner via needle valve 170 and piping 169, or directly to the road via piping 171 and sprayers 172 a and 172 b.

In use, the user rotates the ball valve 162 to allow the liquid to flow through from the tanks to the wetting system. The pump 166 receives a signal from the controller to start drawing liquid from the tanks. The liquid first goes through a strainer 164 that removes any debris that may damage the piping system before going through the pump. Liquid goes through check valve, which is designed to prevent backflow of liquid. If the liquid reverses direction or abruptly stops, the valve will close as a result to prevent damage occurring to the wetting system via water hammer. (Water hammer is a sudden pressure change in any wetting system that can lead to pump damage or hoses leaking). Liquid then flows into the 3-way T-valve 168, which will direct the liquid to either treat the material directly, or to treat the road. A user can rotate the handle of valve 168 to direct the flow to the route of their choice. If the user decides to spray the material, the liquid will first flow through a needle valve 170. The needle valve allows the user to increase or decrease the flow rate of the liquid going to the material, along with having a secondary shut off valve. If the user decides to spray the road, the liquid will flow through piping 171 to the road spray subsystem and sprayers 172 a and 172 b attached to the spinner chute. If the user wishes to remove the road spray system from their chute, the coupling allows the user an easy disconnection and reconnection point to attach the road spray subsystem of the wetting system.

The specifics of the computation methods used by the control system could use different methods than those disclosed above, so long as the methodology and input and output data meet the described objectives. The invention in its broader aspects is therefore not limited to the specific details and representative apparatus and methods shown and described. For example, the controlled conveyor used in conjunction with the invention may be a belt conveyor rather than, e.g., an auger or chain conveyor. Control signals such as weight information, vehicle speed, and the like may route directly to the controller, without the use of a controller area network, or may be obtained from existing on-board vehicle systems such as the OBD-2 system mentioned above. Departures may therefore be made from such details without departing from the spirit or scope of the general inventive concept. The invention resides in each individual feature described herein, alone, and in any and all combinations and subcombinations of any and all of those features. Accordingly, the scope of the invention shall be limited only by the following claims and their equivalents. 

What is claimed is:
 1. A vehicle mounted spreader for spreading materials such as sand, salt, or other granular chemicals onto snow- and ice-covered road surfaces comprising: a hopper for containing material to be spread, one or more load sensors coupled to said hopper for measurement of said hopper contents, a spinner for spreading said material, a conveyor for conveying said material from said hopper to said spinner, a vehicle speed input, and a controller, wherein said load sensor, spinner, conveyor, and speed input are coupled to said controller, and said controller is programmed with an intended density of material and desired width of coverage, and wherein said controller processes measurements from a vehicle speed measurement and load sensor input to generate outputs to control a speed of said conveyor and a speed of said spinner, whereby said controller controls a rate of material distribution and a pattern of material distribution to approach said intended density and width.
 2. The spreader of claim 1 wherein said controller adapts an assumed output rate developed from a current spinner and conveyor rate using load sensor readings, such that said controller refines said output rate and adjusts said speed of said conveyor toward said intended density of material.
 3. The spreader of claim 1 wherein controller controls said speed of said spinner to achieve a desired width of coverage.
 4. The spreader of claim 1 further comprising a human interface, wherein said controller provides feedback information via the human interface to an operator.
 5. The spreader of claim 4 wherein said feedback information comprises a range within which vehicle speed must be maintained to permit accurate control of said rate of material distribution at said target density.
 6. The spreader of claim 1 further comprising a wireless communication system coupled to said controller, said controller delivering feedback information from said controller to a remote server via said wireless communication system.
 7. The spreader of claim 6 wherein information delivered by said controller comprises historical measurements of coverage density and width of coverage, speed, and load sensor data.
 8. The spreader of claim 6 further comprising a positioning system coupled to said controller producing location and motion information, said controller delivering location information to said speed input of said controller, said human interface and/or said remote server.
 9. The spreader of claim 6 wherein said controller receives instructions from a dispatcher via said wireless communication system.
 10. The spreader of claim 1 further comprising a cradle supported by said vehicle, said cradle having at least one load cell, said hopper supported by said at least one load cell.
 11. The spreader of claim 1 wherein said conveyor is an auger.
 12. The spreader of claim 1 wherein said conveyor is a chain conveyor.
 13. A vehicle mounted apparatus for distributing snow and ice melt material onto snow- and ice-covered road surfaces comprising: a container for containing material to be distributed, means for distributing said material, means for conveying said material from said container to said means for distributing said material, and a controller controlling said distributing means and conveying means in response to a measurement of a quantity of melt material in said container, said controller programmed with an intended density of melt material and desired width of coverage; wherein said controller comprises a vehicle speed sensor and vehicle load sensor, delivering speed and load information to said controller, and said controller processes said speed and load information to generate output signals coupled to control a speed of said conveying means and distributing means, to both control said rate of material distribution and said pattern of material distribution to approach said intended density and width.
 14. The apparatus of claim 13 further comprising a cradle supported by said vehicle, said cradle having at least one load cell providing said load sensor input to said control system, a quantity of material in said container being measured by at least one load sensor.
 15. The apparatus of claim 13 wherein said material comprises one or more of sand, salt, or other granular chemicals.
 16. The apparatus of claim 13 wherein said means for distributing material is a spinner.
 17. The apparatus of claim 13 wherein said means for conveying material comprises one or more of an auger and a chain conveyor.
 18. The apparatus of claim 13 wherein said material comprises brine and said container is a tank, and said means for distributing said material is a nozzle array, and said means for conveying said material is a pump and a hose.
 19. The apparatus of claim 13 further comprising a cradle supported by said vehicle, said cradle having at least one load cell, said container supported by said at least one load cell. 